A and B can do a piece of work in 10 days. B and C can do it in 12 days. C can do it in 20 days. How long will A take to do it alone?

• Ans 15 Days
  B & C's 1 day work=1/12, So B's 1 day work=1/12 - 1/20= 1/30
  A & B's 1 day work=1/10, So A's 1 day work=1/10 - 1/30= 1/15
  So A alone can complete the work in 1/(1/15)=15 Days
• 11 years agoHelpfull: Yes(0) No(0)